Flexible electrical conduit.



C. HYDE.

FLEXIBLE ELECTRICAL CONDUIT.

APPLICATION FILED MAR. 15. I916.

Patented May 22 1917.

COURTNEY HYDE, OF BROOKLYN, NEW YORK, ASSIGNOR TO RUSSEL DART, OF NEWYORK, N. Y., COURTNEY HYDE, 0F BROOKLYN, NEW YORK, AND JOSEPH T. MONELL,OF JERSEY CITY, NEW JERSEY, GOPARTNERS DOING BUSINESS AS ALPHADUCT COM-PANY, OF JERSEY CITY, NEW JERSEY.

FLEXIBLE ELECTRICAL connurr.

. Specification of Letters Patent.

Patented May 22, llmlt.

Application filed March 15, 1916. Serial No. 84,298.

of New York, have invented new and useful Improvements in FlexibleElectrical Conduits, of which the following is a specification.

My invention relates to flexible nonmetallic electrical conduit, and hasfor its object the production of such a conduit which does not includeas an element a supporting helix of semi-flexible material, and whichpossesses nevertheless the essential characteristic of resistance tocollapse when bent around curves or subjected to normal radial pressure.

The prime requisite of conduits of this class that they shall preserve acircular form of cross section under all common condi tions of use, hasbeen known and recog-.

nized throughout the entire period of existence of the art, andheretoforeja semiflexible helical element disposed in various relationsin such structures has been relied upon as the only available means foreffect- I have devised a conduit from which the semiflexible helix isomitted and which nevertheless may be flexed or subjected to radialcompression without dis; tortion of the circular cross section, which ismore economical to manufacture, and which also embodies a smoothinterior enabling the conductor to be fished with great ease.

My new and improved type of conduit consists of a longitudinally foldedinner lin ing, a layer of waterproofing compound thereon, an outerbraided jacket and a second layer of waterproofing compound.

The inner lining is formed of a'strip of flat woven fabric embodying aweft of semiflexible. or resilient material as paper fiber,

and a warp of soft or highly flexible material as cotton thread or yarn,folded longitudinally about a mandrel with the edges abutting. Thesemi-flexible weft forms a series of rings which are closely bound orlocked together by the warps and V are adapted to resist radialcompression and tend to preserve an open duct when the con- 1 duit isflexed, that is, one that retains its cylindrical form on curves andbends or otherwise stated does not flatten or collapse when bent in thecourse of installation of the same, when coiled for shipping or duringthe manipulation in the course of manufacture. In order to attain acircular cross section instead of a pear shape in a conduit of thisdescription, I crimp or slightly frapture, without severing, thesemi-flexible weft of the flat fabric at two or more points adjacent theedges of the strip prior to forming the strip into a tube, with theresult that a cross section of substantially circular form is maintainedon completion of the conduit. The mechanism by which this crimpingoperation is performed consists of a pair of specially shaped rollsthrough which the fabric strip is fed during the progress of thematerial in the course of manufacture before the compound is applied ashereinafter more fully described together with other parts of theprocess by which the product described is manufactured. The waterprooflayers consist of any of the well known compounds suitable to thepurpose and familiar to this art. The braided cover is also of the typeknown to the art and may be applied by any preferred standard braidingmachine.

In the accompanying drawing in'which like numerals of reference indicatecorresponding parts in the various figures thereof, Figure 1 shows astrip of the flat fabric for the inner tube or lining, and Fig. 2 aperspective of the same crimped or broken; Fig. 3 is a section of my newform of conduit on line 3--3 of Fig. 4 looking in the direction of thearrows; Fig. 4 a cross section of the conduit; Fig. 5 a detail of thecrimping rolls.

Referring to the drawing, 15 is the flat fabric lining strip composed ofthe semiflexible, resilient transverse elements 7.and the flexibleinterwoven [longitudinal .ele ments 8. For the semi-flexible element 7paper fiber or similar material is well adapted and cotton yarn issuitable for the flexible element 8. The dotted lines 9-9, Fig. 3,indicate the breaks in the fabric 15 which tend to make the tube lesspear shaped and approximately of the form shown in Fig. 4:. 10 (Figs. 2,3 and 4) indicate the edges which in the completed tube abut. If desiredthe inner tube may be reinforced at the line of the abutting edges, bylaying a narrow strip 17 of thin material longitudinally over the joint,the strip being first.

compounded on one or both surfaces as preferred. 11 (Fig. 3) is thefirst compound layer, 12 the braided jacket, 13 the second compoundlayer. 14 is a groove in the roll 19 (Fig. 5) into which the tongue 16in the roll 18 projects when the parts are assembled in operativerelation. The space between the surfaces of the tongue 16 and of thegroove 14 should be limited sufficiently to jam the strip 15 as itpasses and thus to bend or break the semi-flexible elements 7 withoutsevering them. The proper adjustment of the rolls 18 and 19 to effectthis purpose will depend upon the character of the particular fabric inuse, and can readily be determined by experiment.

Suitable methods of making my product will readily occur to thoseskilled in the art of manufacturing non-metallic flexible conduits forelectrical conductors upon read ing the preceding description of theinvention. I suggest as a preferred method that a narrow stripofmaterial, such as15, be first treated with waterproofing or othersuitable compound, by applying a substantial coating to one side only ofthe strip, then forming the strip into a tube by folding itlongitudinally, with the compound exposed, then covering it with a Wovenor braided cotton jacket, and then running the same through a bath ofsuitable compound and finishing the conduit with an application of mica,powdered soapstone or like material to avoid a tacky or sticky surface.

It is obvious that these steps of manufacture can be successively andautomatically performed so as to manufacture an eflicient conduit of theclass referred to more economically than heretofore.

What I claim and desire to secure by Letters Patent is:

1. A conduit embodying a longitudinally "near their extremities.

3. A conduit embodying a tube composed of a series of rings ofsemi-flexible material.

interwoven with longitudinal members of flexible material.

l. In an electrical conduit, the combination of an inner tube consistingof a longi- 'tudinal folded layer of flat fabric composed oflongitudinally extending flexible elements interwoven with transverselyarranged semifiexible elements, a layer of compound applied to the outersurface thereof, a jacket of textile fabric covering'the same and anouter coating of compound.

In testimony whereof I have hereunto set my hand in presence of twosubscribing witnesses, this 28th day of February, 1916.

. COURTNEYHYDE.

Witnesses:

J. J. GAYNon, FREDERICK. CLATz.

